FOREST RESOURCES OF THE PONDEROSA PINE REGION 



Forest Depletion 



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DEPLETION involves the drain caused by cut- 

 ting, forest insects, fires, disease, and wind 

 throw. The rate of drain was determined 

 separately for ponderosa pine and for all other 

 species combined. Determination of depletion of 

 ponderosa pine on account of cutting, fire, and 

 insects was based on past records covering a recent 

 and representative period. For depletion due to 

 disease and wind throw, since no reliable records 

 were available, rates were estimated. For species 

 other than ponderosa pine, records of cutting and 

 fire depletion were available, but insect, disease, 

 and wind-throw depletion had to be estimated 

 for these other species. 



The drain on stands of saw-timber size was cal- 

 culated in board feet, log scale, Scribner rule, and 

 that on smaller sizes in cubic feet. 



1400 

 ■ 200 

 1000 

 800 

 600 























/ 



























































































200 



















































1904 1909 



Figure 19. — Trend of ponderosa pine production in Washington and 

 all of which was from the eastern portions of the two States. (1869—89 

 estimates from Census totals; 1899-1924, Census figures, with 5-year 

 1908 to 1936.) 



Cutting Depletion 



From the beginning of settlement by white men, 

 cutting of the forests has kept pace with the 

 economic growth of the region; the forests furnished 

 building material, fuel wood, fence posts and rails 

 for domestic development, later ties and timber for 

 the construction of railroads, and finally sawlogs 

 for a huge lumber industry. 



Detailed statistics for the years prior to 1925 are 

 not available, but Bureau of the Census records of 

 ponderosa pine lumber production in Oregon and 

 Washington from 1899 to 1924, together with 

 Forest Service estimates for the 3 preceding decades, 

 show the trends in eastern Oregon and eastern 

 Washington, since practically all of the ponderosa 

 pine lumber was milled there (fig. 19). 



Lumber cut prior to 1889 was 

 small averaging less than 100 mil- 

 lion board feet annually. From 

 1889 to 1915 it was fairly stable. 

 During the World War production 

 soared, especially in Oregon, fell off 

 slightly in 1921, only to increase 

 again rapidly up to 1 929, after which 

 it declined sharply. In 1935 the 

 downward trend was arrested and 

 in 1939 an all-time high was 

 attained. 



Since 1925 the Forest Service, in 

 cooperation with the Bureau of the 

 Census, has compiled annual sawlog 

 cut by species and counties in the 

 ponderosa pine region and it is 

 largely upon this statistical record 

 for the period 1925-36 that cut- 

 ting depletion is based. Statis- 

 tics of the estimate of cutting 



Oregon, nearly 

 Forest Service 

 averages from 



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